Major Depressive Disorder (MDD) is a prevalent and debilitating clinical problem in every country in which it has been studied. In recent decades, the rate of first episode of MDD has been increasing among adolescents, so that the highest rate of first onset is now among those in the 15-25 age range. Furthermore, MDD is a highly recurrent disorder, with individuals who experience one episode having over a 50% probability of subsequent episodes. Thus, prevention of the first episode of MDD is an important and significant health issue. We have incorporated findings from human development and empirical clinical research with adolescents into a manualized, school-based program designed to prevent MDD among those who are at risk for the development of the disorder. Within a developmental context, the 14-session program is based on principles of problem solving, interpersonal, behavioral, and cognitive studies of adolescent depression. A school psychologist, who is a school employee, will lead the program within a small-group format. In the proposed project we plan to implement and evaluate the success of this program with a group of Icelandic adolescents who are "at risk" for the first episode of MDD. "At risk" is defined as never having suffered from diagnosable MDD and: 1) scoring 13 or higher on the CDI; 2) scoring 75th percentile or higher on CASQNEG; 3) scoring 25th percentile or lower on CAS-POS; OR, 4) scoring 25th percentile or lower on CASQ-POS minus CASQ-NEG. Participants will be 96 "at risk" ninth grade (age 14) students, who will be randomly assigned to either the prevention program or to an "assessment only" control group. The program will be conducted throughout one entire school year, and then participants will be followed for a second year. All participants will be evaluated at the beginning and end of the program and at the beginning and end of the second school year of the project. This project will provide valuable information for the new selection criteria and feasibility data regarding a larger prevention program throughout Iceland. Data from this project will inform and provide guidelines for a subsequent larger prevention program in Iceland and in other countries.